1. Field of the Invention
The invention relates to a method for sharing mobility status between the subscriber identity cards, and more particularly to a method for sharing mobility status in a system with the subscriber identity cards provided by different network operators.
2. Description of the Related Art
Currently, the Global System for Mobile communication (GSM) standard is the popular standard for mobile phones in the world. The GSM standard, standardized by the European Telecommunication Standards Institute (ETSI) is a cellular network structure and a Time Division Multiple Access (TDMA) system. For a carrier frequency, the TDMA system will divide a frame into eight time slots, wherein each time slot is used to transmit a channel data for a subscriber. Meanwhile, one of the available technologies of a GSM network is the General Packet Radio Service (GPRS) technology. The GPRS technology utilizes the unused channels in the GSM network to provide moderate speed data transmission. The Wideband Code Division Multiple Access (W-CDMA) system is a wideband spread-spectrum mobile air interface that utilizes the direct-sequence spread spectrum method of asynchronous code division multiple access to achieve higher speeds and support more users compared to the implementation of the time division multiple access (TDMA) system used by 2G GSM networks. Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) system is another type of 3G mobile telecommunications standard.
A dual SIM mobile phone is a phone with two Subscriber Identity Modules (SIMs), which correspond to different telephone numbers. The dual SIM mobile phone allows a user to use two communication services without carrying two phones at the same time. For example, the same mobile phone may be used for business and private use with separate numbers and bills, thus providing convenience to mobile phone users.